Re: weight lifting...why such different views on it in boxing???????
Assuming a correctly structured program is used, Lifting weights and/or odd objects (for example, sandbags) works and using boyweight training works. And everything in between i.e a mixture/blend of the two.
This is the problem with boxing and indeed most combat sports these days. The purists who swear by good old bodyweight work swear blind weights will hinder the athlete, at the same time as the guy who swears by lifting weights or odd objects gasps at the thought of only doing bodyweight work claiming the athletes it produces will be inferior to those using the iron.
Bodyweight...weights/odd objects.....both are just TOOLS. Concern yourself with the end result instead of worrying about the modality your using to get there.
Me?? I like both bodyweight training, either bodyweight alone AND/OR using power bands (i get mine from ironwoodyfitness.com), weighted vests etc AND using weights whether that be kettlebells, dumbells, barbells or sandbags etc etc.
Structure your program to suit your sport (in my, or indeed your case i assume, that'll be boxing), implement it, monitor and adjust accordingly.
To re-cap. Focus on the goal not the tool used to get there.